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> Once our medical technology has passed the stage of what
> Aubrey de Grey calls actuarial escape velocity - the point at which
> the effects of aging are being defeated faster than we age - our
> life spans will be limited only by accident and violence.
Actually, we should be careful how we state this. Actuarial escape velocity can mean many things, depending on what we are "escaping" from. It's an issue I'm trying to flush out, in my typical wordy manner, at my website.
At the most basic level--the first level de Grey talks about--we are escaping the increasing age-specific mortality rates. Even this has two levels.
The first level, the practical level, is to make sure that, for all or most age cohorts, a person's chance of dying doesn't increase with time. This doesn't necessarily mean that aging has been stopped. In fact, it *most likely* doesn't mean it has been stopped, though it would certainly help if it's been slowed quite a bit.
What it means is that the combined effect of slowed physiological aging and rapidly increasing medical technology is making it possible that, statistically speaking, you're as likely to die next year as this year. In other words, you might still be aging (at a reduced rate), but advancing medicine is allowing physiologically older people to survive longer, so you're just as likely to live longer as if you had stopped aging. To put it plainly, you have stopped aging in practical terms.
For example, if medical technology were to increase so rapidly in the next five years that, five years from now, a 65-year-old is as likely to die as that person was when aged 60 today, then we have reached the "cusp" of actuarial escape velocity. Of course, just as an airplane can stall or run out of fuel, if the technology can't maintain this high rate of progress, then we'll fall back below the cusp.
The second level is to reach the point where we actually stop aging physiologically: where our age-specific mortality rate remains less than or equal to what it was the year before, even if we ignore advancements medical technology.
This second level is what I suspect a lot of us in the anti-aging community think of when we think of actuarial escape velocity: reaching the point where we stop aging.
But, in order to get to the point where "our life spans will be limited only by accident and violence", we have to move to the next level. We have to not only stop, but actually reverse aging. By the time we can reverse aging, our medicine will probably be sufficiently advanced that disease in general will be mostly eliminated. At that point, what you have left is, for the most part, accidents and violence.
I think Robert Freitas did a nice numerical analysis, for the ueber-geeks out there. There's a copy of the article at the Longevity Meme:
http://www.longevitymeme.org/articles/viewarticle.cfm?page=1&article_id=9
[Posted by: Jay Fox at December 10, 2004 11:21 AM]
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